The present invention relates to a clothes washing machine, or a similar appliance such as a washer/dryer, particularly intended for a household utilization, of the type having a perforated drum rotatable around a horizontal axis.
As is well known, a machine of this type includes an outer cabinet provided with an opening for a front or an upper loading door to load and unload the clothes to be washed. An inner tub contains the washing solution and the aforesaid drum. An elastic duct, usually known as the bellows, is positioned between the opening provided in the outer cabinet for the loading door and an associated opening provided in the inner tub.
A current construction of bellows that are presently utilized on washing machines having a front mounted loading door is disclosed in the British patent application no. 2 296 018. It is also generally known, on the machines with a top mounted loading door, to have a plurality of peripheral circumvolutions along a substantial portion of the bellows length in order to let the inner tub oscillate with respect to the outer cabinet when the machine is operated. The bellows also include, integrally made with the said circumvolutions, a first and a second flanged end. The former end is secured to the opening provided in the outer cabinet for the loading door and the latter end is secured to the opening provided in the inner tub.
Being entirely made as a single piece, the known bellows need to be made with a material, which is a mixture having elastomeric properties, able to meet various or even opposing requirements. In particular, such a material has to meet the severe requirements imposed by the latter mentioned end of the bellows. The end of the bellows secured to the loading opening in the inner tub must resist to the repeated abrasions, caused by contact with clothes kept in movement within the rotary drum, and to the corrosion due to the washing solution. At the same time, the bellows must have a good dimensional stability to guarantee a seal against water leakages. As a consequence, it is a common practice for the manufacturers of washing machines to make the entire bellows as a single piece with elastomeric mixtures of a hardness above Shore A 33-35, so as to satisfy all of the above mentioned requirements.
In the bellows of such a construction, a common drawback is that substantially all vibrations, which are generated inside the inner tub when the machine is operated, are transmitted to the outer cabinet. More precisely, the following negative effects are noticed:
a high airborne noise is emitted by the machine; PA1 the vibrations (oscillations and accelerations) can spread through the structure of the house and to the furniture surrounding the washing machine, particularly in case of a wooden or another not very rigid floor; PA1 a low limit of the unbalanced load of clothes has to be accepted by a manufacturer of a washing machine. This means, especially in case of machines controlled by a "fuzzy" logic, a high probability to repeat the attempts of spinning in order to obtain the required distribution of the clothes to be washed inside the rotary drum.